diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2012-03-29 16:53:48 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-03-29 16:53:48 -0700 |
commit | 12679a2d7e3bfbdc7586e3e86d1ca90c46659363 (patch) | |
tree | d9c00f2e599d1c3e04a349229a6a19906d01f99e /arch/arm/kernel/patch.c | |
parent | 1c036588772d01655d851f75dffc27c971e072e2 (diff) | |
parent | b0df89868006517417251e02cc4ce5d4b0165885 (diff) |
Merge branch 'for-linus' of git://git.linaro.org/people/rmk/linux-arm
Pull more ARM updates from Russell King.
This got a fair number of conflicts with the <asm/system.h> split, but
also with some other sparse-irq and header file include cleanups. They
all looked pretty trivial, though.
* 'for-linus' of git://git.linaro.org/people/rmk/linux-arm: (59 commits)
ARM: fix Kconfig warning for HAVE_BPF_JIT
ARM: 7361/1: provide XIP_VIRT_ADDR for no-MMU builds
ARM: 7349/1: integrator: convert to sparse irqs
ARM: 7259/3: net: JIT compiler for packet filters
ARM: 7334/1: add jump label support
ARM: 7333/2: jump label: detect %c support for ARM
ARM: 7338/1: add support for early console output via semihosting
ARM: use set_current_blocked() and block_sigmask()
ARM: exec: remove redundant set_fs(USER_DS)
ARM: 7332/1: extract out code patch function from kprobes
ARM: 7331/1: extract out insn generation code from ftrace
ARM: 7330/1: ftrace: use canonical Thumb-2 wide instruction format
ARM: 7351/1: ftrace: remove useless memory checks
ARM: 7316/1: kexec: EOI active and mask all interrupts in kexec crash path
ARM: Versatile Express: add NO_IOPORT
ARM: get rid of asm/irq.h in asm/prom.h
ARM: 7319/1: Print debug info for SIGBUS in user faults
ARM: 7318/1: gic: refactor irq_start assignment
ARM: 7317/1: irq: avoid NULL check in for_each_irq_desc loop
ARM: 7315/1: perf: add support for the Cortex-A7 PMU
...
Diffstat (limited to 'arch/arm/kernel/patch.c')
-rw-r--r-- | arch/arm/kernel/patch.c | 75 |
1 files changed, 75 insertions, 0 deletions
diff --git a/arch/arm/kernel/patch.c b/arch/arm/kernel/patch.c new file mode 100644 index 00000000000..07314af4773 --- /dev/null +++ b/arch/arm/kernel/patch.c @@ -0,0 +1,75 @@ +#include <linux/kernel.h> +#include <linux/kprobes.h> +#include <linux/stop_machine.h> + +#include <asm/cacheflush.h> +#include <asm/smp_plat.h> +#include <asm/opcodes.h> + +#include "patch.h" + +struct patch { + void *addr; + unsigned int insn; +}; + +void __kprobes __patch_text(void *addr, unsigned int insn) +{ + bool thumb2 = IS_ENABLED(CONFIG_THUMB2_KERNEL); + int size; + + if (thumb2 && __opcode_is_thumb16(insn)) { + *(u16 *)addr = __opcode_to_mem_thumb16(insn); + size = sizeof(u16); + } else if (thumb2 && ((uintptr_t)addr & 2)) { + u16 first = __opcode_thumb32_first(insn); + u16 second = __opcode_thumb32_second(insn); + u16 *addrh = addr; + + addrh[0] = __opcode_to_mem_thumb16(first); + addrh[1] = __opcode_to_mem_thumb16(second); + + size = sizeof(u32); + } else { + if (thumb2) + insn = __opcode_to_mem_thumb32(insn); + else + insn = __opcode_to_mem_arm(insn); + + *(u32 *)addr = insn; + size = sizeof(u32); + } + + flush_icache_range((uintptr_t)(addr), + (uintptr_t)(addr) + size); +} + +static int __kprobes patch_text_stop_machine(void *data) +{ + struct patch *patch = data; + + __patch_text(patch->addr, patch->insn); + + return 0; +} + +void __kprobes patch_text(void *addr, unsigned int insn) +{ + struct patch patch = { + .addr = addr, + .insn = insn, + }; + + if (cache_ops_need_broadcast()) { + stop_machine(patch_text_stop_machine, &patch, cpu_online_mask); + } else { + bool straddles_word = IS_ENABLED(CONFIG_THUMB2_KERNEL) + && __opcode_is_thumb32(insn) + && ((uintptr_t)addr & 2); + + if (straddles_word) + stop_machine(patch_text_stop_machine, &patch, NULL); + else + __patch_text(addr, insn); + } +} |